Device for transporting parts for supplying machines

ABSTRACT

A device for transporting parts ( 1 ) includes a transporting member ( 3 ) whereon the parts to be transported ( 2 ) are to be arranged. The transporting member ( 3 ) is mounted mobile relative to a frame ( 9 ) of the device for reciprocating movement, which occurs in a plane (P) in which the parts are transported. A driving device comprises at least a drive cam ( 4 ) co-operating with at least a roller that is displaced with the transporting member, so that the movement in the plane is a reciprocating translational movement generated by the rotation of the drive cam ( 4 ).

BACKGROUND OF THE INVENTION

The present invention concerns a device for transporting parts forsupplying machines intended to permit supply of machine parts, or ingeneral intended to ensure the transport of all types of parts inindustrial process.

At the present time, several kinds of appliances are known which areintended for the transport of parts and notably devices intended for thesupply of machines. Common transport devices include conveyor beltdevices formed by a belt or a band driven by rollers or by vibratingrail type devices generally called vibratory type devices.

The conveyor belt devices present drawbacks with respect to occupationof space which renders installation not possible in a great number ofsituations. They also present certain drawbacks strictly connected withthe piecemeal supply of parts, in other words, with the transition whichtakes place at the end of the band between the conveyor belt and thesupplied machine.

The vibratory devices operate on a relatively simple principle whichconsists of alternatively displacing the rail axially while separatingthe transported pieces in the air pending return of the rail to itsformer position. Thus, these vibratory units present oscillatingmovements with a vertical component destined to cause separation ofpieces and horizontal components by axial displacement of the rail. Insaid manner, the pieces remain in contact with the rail only during itsaxial displacement towards the front. These vibratory rails, however,present numerous drawbacks related to their design and theirutilization. In fact, they do not permit transport of parts at rapidrates and are therefore limited to certain applications. Moreover,certain parts to be transported are fragile and are thereforesusceptible to being damaged during their displacement along the rail byrepeated shocks due to the vertical oscillations of said rail. Inaddition, certain pieces can no longer be transported by such rails byreason of their shape. In fact, very fine pieces will overlap and becomejammed during the course of their travel; moreover, very heavy piecesrequire powerful vibratory units, which would interfere with theoperation of the rest of the machine. Also, these vibrating railappliances present the disadvantage of being able to transport thepieces in only one direction, in contrast to the conveyor belt devices,and they also present problems in exiting from rail with certain partspossibly being encountered in the overhang with the risk of beingdamaged by longitudinal rail end deflection.

Consequently, it is the objective of the present invention to resolvethe aforementioned drawbacks of parts supply devices with the aid ofsimple, reliable means which are not expensive and which are easilyimplemented. The invention proposes a parts supply device which permitsrapid transport of parts, which tends to function in both directions,which is capable of transporting fragile pieces and light-weight parts,while occupying little space, and which facilitates its adaptation todifferent situations encountered in the industrial process.

SUMMARY OF THE INVENTION

According to its principal characteristic, the device for transportingparts comprises a transporting member on which the parts to betransported are intended to be arranged. The transporting member ismounted mobile relative to a frame of the device for reciprocatingmovement in the plane in which the parts are transported by a drivingdevice. The driving device comprises at least a drive cam, co-operatingat least with a roller, which is an integral part of the transportingmember, to provide it with its movement.

According to a preferred embodiment of the device for transporting partsaccording to the invention, the transporting member is a longitudinalrail whose movement in the plane of displacement of the parts is areciprocating translational movement, generated by the rotation of thedrive cam.

According to another embodiment of the device for transporting partsaccording to the invention, the transporting member is a rail having around shape, either circular or spiral, whose movement in the plane ofdisplacement of parts is a reciprocating translational movementgenerated by the rotation of the drive cam.

According to a complementary characteristic of the device fortransporting parts according to the invention, it is characterized inthat the transporting member is carried by a rail support which carriesa roller which drives the parts in translational movement according tothe longitudinal displacement axis when it co-operates with the rotarycam.

According to another characteristic of the device for transporting partsaccording to the invention, it is characterized in that it comprises amotorized device which drives the cam to rotate around its axis ofrevolution the rotation of the cam due to the specific shape of itscontact surface, causes the alternative longitudinal displacement of therail support by co-operating with the roller.

According to the preferred embodiment of the device for transportingparts, the axis of rotation of the cam and the axis of rotation of thedrive roller are parallel.

According to another characteristic of the device for transporting partsaccording to the invention, it is characterized in that the cam presentsan involute rounded surface which comprises: (1) a first zone calledacceleration zone, which is very short, then (2) a zone calledadvancement zone, where the radius of the cam increases in constantmanner over its angular sector, then (3) a brief deceleration zone, infront of (4) a zone called “draw-back”, where the radius decreases.

According to a complementary characteristic of the device fortransporting parts, the forward movement of the rail corresponding tothe acceleration zone, the forward advancement zone and decelerationzone of the involute surface represents an angular sector of the camcomprising between 200° and 300° whereas the zone called the “draw-back”zone represents an angular sector comprising between 60° and 160°.

According to an embodiment of the device for transporting partsaccording to the invention, when the cam travels one complete turn, theroller and thus the rail undergo a forward movement corresponding to theacceleration zone, the forward advancement zone and the decelerationzone of the cam during approximately two thirds of turn, then a veryabrupt “draw-back” movement during the last third of the turn. Thismovement of the rail permits—thanks to the acceleration zone—rapidadjustment of the rail to the relative parts displacement rate (inregard to the frame) and to accelerate same again before moving at aconstant rate during the forward advancement zone, and to then let themslide during the braking or deceleration zone, followed by the rail“draw-back” which takes place quickly before commencement of anothercycle.

According to a complementary characteristic of the device fortransporting parts, the rotary cam is controlled by a motorized devicewhich permits its rotation in both directions according to the user'schoice.

According to another embodiment, the cam is sandwiched between tworollers, while said cam is composed of two superposed cams, a first camor upper cam, with which a first roller 6 a cooperates, and a second camor lower cam, with which a second roller co-operates.

Further advantages will be apparent upon reading the following detaileddescription.

BRIEF DESCRIPTION OF THE DRAWINGS

Other characteristics and benefits of the invention are apparent fromthe description which follows in regard to the attached drawings, whichare provided by way of example only and are not limited thereto.

FIGS. 1 to 6 depict a first embodiment of the device for transportingparts according to the invention.

FIG. 1 represents the device in perspective.

FIG. 2 a represents the device in lateral view.

FIG. 2 b illustrates the device for transporting parts in frontal view.

FIG. 3 represents an exploded view of the transport device.

FIG. 4 presents a sectional view of the rail mechanism.

FIG. 5 illustrates the pivoting cam, viewed from below.

FIG. 6 shows a schematic representation of the contact surface of thecam, depicting effective cam radius versus angle around itscircumference.

FIGS. 7 to 10 illustrate a second embodiment.

FIG. 7 is an exploded perspective view similar to FIG. 3.

FIG. 8 is a lateral sectional view.

FIG. 9 is an illustration seen from above, depicting the cams and therollers.

FIG. 10 is a perspective view showing the cams and the rollers.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

A device for transporting parts 1 transports parts 2 to supply a machinetool or other appliance within the framework of an industrial process.It comprises a transporting member 3 on which the parts to betransported 2 are arranged, which member moves the parts in a plane (P)in which they are located so as to displace them relative to saidmember.

The transporting member 3 is mobile relative to the frame of the deviceto be put into motion in the plane (P) by a driving device (DE)comprising at least one cam 4. The movement of the transporting member 3occurs only in the plane (P) in which the parts 2 are displaced. Thus,the parts 2 are displaced on the transporting member 3 by sliding at themoment when said member moves.

According to the first embodiment of the device illustrated in FIGS. 1to 5, the transporting member 3 is beneficially composed of alongitudinal rail whose movement in the plane (P) is a reciprocatingtranslational movement generated by the rotation of the drive cam 4.Said reciprocating translational movement of the rail 3 provokes slidingdisplacement of the parts 2 along the rail thanks to the particularconfiguration of the mechanical parameters (acceleration, speed) of thealternating movement, obtained thanks to the drive cam 4 and thephysical parameters of the constitutive elements (friction coefficient).It should be noted that such device could utilize a differenttransporting member energized by another type of movement.

Thus, according to a non-represented embodiment, the movement of thetransporting member is a movement of alternative rotation. It isaccordingly beneficially composed of a rail having round, circular orspiral shape, which is energized by rotational alternative movement ofreduced amplitude, said movement being generated by the rotation of adrive cam similar to that of the first embodiment, which co-operateswith an incline which is an integral part of a circular rail supporthinged around a fixed axis.

According to the first embodiment of the device for transporting parts1, the transporting rail 3 on which the parts 2 are arranged to betransported is carried by a rail support 5 which carries a roller 6.Said roller 6 is installed on the support 5 so as to be able to drive intranslation according to the longitudinal axis (XX′) when it cooperateswith the rotating cam 4 as is indicated in FIGS. 1, 3 and 4.

The device for transporting parts 1 comprises a motorized device 7 whichdrives the cam 4 to rotate around its axis of revolution (YY′). Therotation of the cam 4 provokes—thanks to its specific shape—thealternative longitudinal displacement of the rail support 5 whilecooperating with the roller 6. It should be noted that the axes ofrotation of the cam and the roller are parallel, thus reducing wear andtear due to friction at time of their cooperation.

It goes without saying that the device could present a differentconfiguration with respect to cooperation of the cam and the railsupport. The axis of rotation of the cam could be positioneddifferently, while the latter would operate on a sloping plane of thesupport and no longer on a roller, for example.

According to the embodiment illustrated in FIGS. 1 to 6 of the supplydevice of parts 1, said device comprises compensation or biasing meansintended to act upon the roller 6 in order to maintain permanent contactwith the cam 4 so that the alternating movement of the rail 3corresponds exactly to the involute curve of the surface in contact withthe cam 4. These compensation means can be of several kinds, such asformed by a traction spring 8. It should be noted that this spring 8 canact directly between the frame 9 on which the motor 7 is fixed and therail 3, while the rail support 5 is mounted in sliding fashion on aguide 10 of the frame in order to be able to act on the cam 4 via theintermediary of the transporting rail 3 and the spring 8. It should benoted that the cooperation of the rail support 5 with the guide 10 couldbe realized very simply by two lateral flexible sheets which wouldsecure the connection between the frame 9 and the vibrating rail 3.

In the device for supply of parts 1, the rail 3 is mounted in slidingfashion on the frame 9 via the intermediary of its support 5 and guide10. Its movement in the plane (P) is a translational movement, theaccelerations and slow-downs of which are exclusively controlled by theslope of the external surface or the contact surface of the drive cam 4.

According to the illustrated embodiment, the drive cam 4 presents aninvolute surface curve such as is illustrated in FIG. 6. Starting froman initial 0° point at the far let of FIG. 6, it comprises a first zone(A) called the acceleration zone, which is very short, representing anangular segment of less than 20°, followed by a forward movement oradvancement zone (B) in which the rail 3 moves at constant speed, withthe radius of the drive cam increasing in somewhat constant fashion overan angular segment approximately equal to 220°, in a manner so that therail moves with low to zero acceleration. It then comprises a shortdeceleration zone (C), the angular segment of which is less than 20°, infront of a zone called “recoil” or “draw-back” zone (D) the draw-backoccurs with strong acceleration during the first half of the angularsegment (D1), and with some slowing down in a second portion (D2),before returning to the initial 0° point of the drive cam. It can thusbe stated that the forward movement of the rail corresponding to zones(A, B, C) represents an angular segment of the drive cam ranging between200° and 300°; whereas the “draw-back” zone (D) comprises between 60°and 160°. According to the preferred embodiment of the transportingdevice, the group of zones (A, B, C) represent an angular segment ofmore than 240°.

When the drive cam travels one complete turn, the roller 6 and the rail3 undergo movement in forward direction corresponding to zones (A, B, C)of the drive cam during approximately two thirds of the turn, then amore rapid draw-back movement during the last third of the turn. Saidmovement of the rail permits,—thanks to the acceleration zone (A)—rapidattainment of relative movement rate (with respect to the frame) ofparts 2 and to again accelerate before moving at constant speed duringthe deceleration zone (C), then the draw-back (zone D) of the rail whichoccurs quickly before restarting the cycle. It should be noted that theslopes of the contact surface of the drive cam are specificallycalculated so that when the rail 3 retreats, which occurs quitesuddenly, the parts 2 continue to move forward at relative speed withrespect to the frame, prior to being recovered by the rail in theacceleration zone (A) at the moment when it attains their speed.

It should be noted, as indicated in FIG. 5, that the drive cam has holesfor passage of pins, said pins permitting the exact placement of saiddrive cam on the machine tool with exact and reproducible positioning ofthe reference line or point 0 of the drive cam. Said drive cam can,furthermore, be installed on the motorized device, in detachablefashion, in order to be interchangeable, thus permitting, for example,the adaptation of the transporting device to different pieces and todifferent constraints of the machines to be supplied.

FIGS. 7 to 10 represent a second specific embodiment of the invention.

With respect to this second embodiment, for reasons of clarity,identical reference numbers have been designated for the same elementsas were used in the first embodiment and when viewing the figures forthe second embodiment the reader can readily refer to the descriptiongiven for the first specific embodiment.

According to the second embodiment, the spring 8 of the compensationmeans of the first specific embodiment, for maintaining the roller 6 incontact with the drive cam 4 has been replaced by a structure of tworollers 6 a, 6 b and two cams 4 a, 4 b.

Accordingly, the cam 4 is composed of two superposed cams, specifically,a first cam or upper cam 4 a and a second cam or lower cam 4 b. The twocams 4 a and 4 b are preferably integral and mounted on the motor exitshaft 7.

Furthermore, the rail support 5 carries two rollers 6 a, 6 b intended tocooperate with the cams 4 a, 4 b, i.e., a first roller 6 a whichcooperates with the first cam 4 a and a second roller 6 b whichcooperates with the second cam 4 b. Consequently, the two rollers arearranged on both sides of the two cams and plane (P) goes through thecenter of the rollers passes through the pivoting axis (Y,Y′) of the twocams. The general horizontal plane (H1) of the first roller is arrangedin the general horizontal plane of the first cam, while the generalhorizontal plane (H2) of the second roller is arranged in the generalhorizontal plane of the second cam. The general horizontal plane (H1) ofthe first roller and thus the general horizontal plane of the first camis located above the general horizontal plane (H2) of the second rollerand thus the general horizontal plane of the second cam.

It is therefore obvious that the 2-cam unit is sandwiched between thetwo rollers, which permits assurance of displacement in two directionsof the rail support without the spring system as provided in the firstspecific embodiment. Thanks to the two-roller device, acceleration iscontrolled and the inertia of the moving parts has no detrimentaleffect. And, this occurs without interfering friction, which can producea somewhat stiff spring.

In addition, it should be noted that the motored device which permitsturning of the cam can beneficially function in both directions. Thus,when the drive cam turns in one direction, the parts move forward,whereas reversal of the direction of rotation of the cam brings aboutretreat of the parts. It should also be noted that the motorized devicecan beneficially permit regulation of the speed of rotation of the cam.

It should likewise be noted that the rail can be covered with a facing,the friction coefficient of which is adapted to the range of parts it isintended to transport.

Needless to say, the invention is not limited to the specificembodiment, described and presented by way of example, but it alsoincludes all equivalent techniques as well as combinations thereof.

1. A device for transporting parts comprising: a transporting member onwhich the parts are transported, said transporting member being movablymounted relative to a frame of the device for reciprocating movementalong a plane, in which the parts are transported; a driving device fordriving the transporting member with the reciprocating movement, thedriving device including: at least one drive cam, at least one rollermounted to the transporting member and cooperating with the drive cam,the axis of rotation of the cam and an axis of rotation of the rollerbeing parallel, so that the movement in the plane is a reciprocatingtranslational movement generated by the rotation of the drive cam, amotorized device which drives the cam to rotate around an axis ofrevolution, said rotation of the cam having a contact surface configuredto cause alternative longitudinal displacement of a rail support incooperation with the roller, the transporting member being connectedwith the rail such that movement of the rail in the plane includesalternating movement along the plane caused by rotation of the drivecam, and wherein the cam contact surface presents an involute surfacecurve which includes an acceleration zone, then an advancement zone inwhich a radius of the cam increases in constant, linear fashion, adeclaration zone, and a zone called the “draw-back zone” in which theradius diminishes; and wherein the transporting member moves forwardwhen the roller contacts the acceleration, advancement, and decelerationzones, which zones span an angular segment of the cam ranging between200° and 300° and the draw-back zone spans an angular segment rangingbetween 60° and 160°.
 2. The device for transporting parts according toclaim 1, further including: a compensating means for causing the rollerto maintain contact with the cam contact surface.
 3. The device fortransporting parts according to claim 1, wherein when the cam travelsone full turn, the roller and thus the transporting member undergo aforward movement from an initial position corresponding to theacceleration, advancement, and deceleration zones of the cam contactsurface, during approximately two thirds of the turn, then a more abruptreverse movement corresponding to the draw-back zone during the lastthird of the turn, during the acceleration zone accelerating the partsto a displacement speed, advancing the parts constantly at thedisplacement speed during the advancement zone, and allowing the partsto slide during the deceleration zone, then the draw-backzone quicklyreturns the transport member to the initial position to re-start thecycle.
 4. The device for transporting parts according to claim 1,wherein the motorized device rotates the cam in one direction to movethe parts forward along the transport member, and rotates the cam in anopposite direction to move the parts rearward along the transportmember.
 5. The device for transporting parts according to claim 1,wherein the cam is sandwiched between two rollers.
 6. The device fortransporting parts according to claim 5, wherein the cam is composed oftwo superposed cams including an upper cam which cooperates with a firstof the two rollers and a lower cam which cooperates with a second of thetwo rollers.
 7. The device for transporting parts according to claim 1,wherein the said driving device further includes: compensation meansconfigured to act upon the roller in order to maintain permanent contactwith the cam contact surface such that the alternating movement of therail corresponds exactly to the involute curve of the contact surfacepresented by the cam.
 8. The device for transporting parts according toclaim 7, wherein the compensation means includes a spring.
 9. Areciprocating feeder for transporting parts, the reciprocating feedercomprising: a longitudinally elongated transport member; a mountingstructure for mounting the transporting member on a frame forlongitudinal reciprocating motion in a plane; at least one rollermounted for longitudinal movement with the transporting member; aneccentric cam mounted on a rotary drive which is connected with theframe, the cam being mounted to engage the roller and urge the rolleralong the plane of the longitudinal reciprocating movement, the camlying in a plane parallel to the plane of longitudinal reciprocatingmovement, the cam having an involute surface including: an accelerationzone of increasing radius spanning an angular segment of less than 20°which accelerates the transport member in a first direction along theplane, a forward movement zone of constant increasing radius spanning anangular segment between 200° and 260° which moves the transport memberin the first direction at a constant speed without acceleration, adeceleration zone spanning an angular segment of less than 20° whichdecelerates movement of the transport member in the first direction, a“draw-back zone” with decreasing radius, the draw-back zone including afirst draw-back zone portion and a second draw-back zone portion, whichdraw-back zone moves the transfer member in the second direction, thedraw-back zone spanning an angular segment between 60° and 160°; acompensating means for maintaining the roller in contact with theeccentric cam involute surface and moving the transporting member in thesecond direction along the plane of longitudinal reciprocating movement.10. The feeder according to claim 9, wherein the compensating meansincludes one of a spring, a second roller, and a second roller and camassembly.